This invention relates to a releasable coupling for tubes or pipes. More particularly, but not exclusively, the invention concerns a coupling for use in fluid installations, such as hydraulic or pneumatic equipment, to provide a fluid-tight releasable connection between tubes or pipes and component parts or glands of the equipment.
The releasable coupling of this invention is of the kind, generally called a push-in coupling, in which the tube or pipe is inserted into an entry in the coupling and the tube or pipe is held within the coupling by a gripping or clamping action of claws or teeth engaging the exterior surface of the tube or pipe. For releasing the coupling, the teeth are displaced by some means or part or device acting thereon.
Various designs of such push-in couplings are known and many constructions are complex and expensive to manufacture. As will be understood, special requirements to ensure both a fluid-tight connection and the releasable engagement of the clamping teeth have to be provided, whilst providing a coupling which is compact and of relatively short axial length. In prior designs, the elements of the coupling for fulfilling the two functions of sealing and clamping displacement or disengagement are usually separated in the construction of the coupling assembly. This has led either to couplings of significant axial length or to couplings having complex configurations.